In 1913, the Federal Reserve Note was authorized as U.S. currency. The new notes were supposed to be backed by gold or other “lawful money”, based on the stipulations of the Federal Reserve Act of 1913.

However, this only lasted about 20 years. By the time of the Great Depression, the Fed considered itself to be in a tight spot. It simply did not have enough gold to back all Federal Reserve Notes and Gold Certificates in circulation, and at the same time wanted flexibility with monetary policy to fight deflation and unemployment.

In 1933, the Emergency Banking Act was passed by President Roosevelt, and Executive Order 6102 was also signed. The latter move famously criminalized monetary gold, and ended the gold standard.

After all, if gold can’t be legally owned, it can’t be legally redeemed.